Monitor what process is using up my upload

Dear all,

dunno if this is the right place to post, but I hope you can help me out.

Apparently one or more of our devices are using up all our upload making our internet extremely slow in periods during the day. The technician from our internet provider guessed it could be some cloud service syncing.

Afaik this have never been an issue beforehand, so I'd like to see if it's possible to detect which process is causing all that traffic jamming our connection multiple times during the day.

Is this possible?